It is common practice for buildings and/or residential structures to be comprised of discrete structural building materials, such as framing members and sheet goods. The building materials are typically connected by use of mechanical fasteners, such as nails, screws, staples. Other mechanical fasteners that may be used are plates, anchors, hangers, bolts, split rings and clips or the like. Adhesives are also used in combination with mechanical fasteners to help connect certain types of building materials. For example, liquid construction adhesives are commonly utilized in joist-to-subfloor panel connections to improve the strength and durability of these joints. In some cases, liquid construction adhesives are used in tongue-and-groove joints between adjacent subfloor panels. In other cases, certain liquid construction adhesives are applied to the interior face of wall studs prior to installation of interior sheetrock. The use of adhesives at the stud-to-sheetrock interface allows the builder to reduce the number of mechanical fasteners. The result may be an interior wall with fewer surface defects. In all of these cases, the construction adhesive is applied to the building material during the construction process.
In spite of the advantages associated with construction adhesives, their usage is somewhat limited, due in part to the difficulty and time required to apply them to building materials during the construction process. Although it is important for connections between building materials to be strong and highly durable, it is also important to have connections that are easy and relatively quick to assemble. In most cases, construction adhesives are applied to building materials at a job site with a manual dispensing device that is commonly referred to as a caulking gun. This device is relatively slow and labor intensive. In cold or freezing weather there is a tendency for the viscosity of liquid construction adhesives to increase, which makes them even more difficult to apply with a manual caulking gun. Thus, some builders choose not to use construction adhesives because of the time and difficulty associated with their use.
Conventional construction adhesives generally are designed to be applied to building materials at a specific spread rate, and for the joint to be closed within a certain period of “open assembly time”. The “open-assembly-time” is the time between adhesive application to one or both substrates and the closing of the joint by mating with the corresponding substrate. Long “open-assembly-times” can result in partial or complete solidification of the applied adhesive prior to contact with the corresponding substrate in the joint. When this occurs the adhesive might not contribute anything to the strength of the joint, and in many cases it will obstruct the fit of the joint. Unfortunately, many builders or installers struggle to adhere to these requirements during the construction process, and the resulting joint strength and durability are less than that which was anticipated.
One specific example of a failure mode involves the application of adhesives to substrates in relatively hot, dry weather in a work environment requiring relatively long “open-assembly-times”. Another failure mode associated with conventional construction adhesives relates to their use on building materials that are wet from exposure to rain or snow. It has been discovered that most known construction adhesives yield weaker joints when they are applied to wet building materials. Yet another failure mode relates to incomplete or non-uniform adhesive application rates. In this situation at least some portion of the joint substrate receives an insufficient amount of adhesive. Accordingly, there is a need for building materials that can be assembled without the application of construction adhesives at the job site, and yet yield high-strength, durable joints, even when assembled under adverse weather conditions.